Rollup merge of #138269 - Ayush1325:uefi-fs-permission, r=joboet

uefi: fs: Implement FileType, FilePermissions and FileAttr

- In UEFI, both FileType and FilePermissions are represented by the attr bitfield.
- Using simple bools here since both are represented by a single bit.
- Add `FILE_PERMISSION` mask for constructing attribute while change permissions.

cc ````@nicholasbishop````

Author: matthiaskrgr